Educational Strategies to Promote Clinical Diagnostic Reasoning
N Engl J Med 2006; 355:2217-2225. https://www.nejm.org/doi/full/10.1056/nejmra054782
Judith L. Bowen, M.D
Department of Medicine, Oregon Health and Science University, Portland, USA
Updated by NEJM Healer, 16 June 2022
Summarized by the Editor, The KAUVERIAN, 18 June 22
Introduction
- The personal histories that clinicians and patients bring to each encounter play a significant role.
- The diagnosis is co-created by the patient and the diagnostic team, which can include a broad array of health care professionals.
- Clinical teachers are to observe learners and provide feedback as part of an “educational alliance,” aimed at improving learning.
Clinical Teachers
Clinical teachers differ from clinicians in a fundamental way. They must simultaneously foster high-quality patient care and assess the clinical skills and reasoning of learners in order to promote their progress toward independence in the clinical setting.
Clinical teachers must diagnose both the patient’s clinical problem and the learner’s ability and skill.
Medical practice now focuses on shared decision-making and collaborative practice. Thus, teachers should promote awareness of interdependence among patients, families, and other members of the health care team when reasoning through clinical problems with learners.
A major departure from the classic physician-centered approach, this new team includes the patient, treating clinicians, nurses, pharmacists, physical therapists, radiologists, pathologists, and others.
In the clinical setting, the patient’s health and care are the focus. Clinical problems may involve many organ systems.
This report focuses on how clinical teachers can facilitate the learning process to help learners make the transition from being diagnostic novices to becoming expert clinicians.
Diagnostic Reasoning
Clinical teachers observe learners gathering information from patients, medical records, imaging studies, results of laboratory tests, and other health care providers. On the basis of their observations, and through the discussion of clinical cases, teachers draw conclusions about the learners’ performance, including their reasoning processes.
The first step in diagnostic reasoning, which is based on knowledge, experience, and other important contextual factors, is always data acquisition which may include elements of the history, the findings on physical examination, and the results of laboratory testing and imaging studies.
Another early step is stating the problem, also called problem representation, usually as a one-sentence summary defining the specific case.
To state the problem concisely and appropriately, the resident must have clinical experience with similar patients and must be able to recognize the information that establishes one disease as the diagnosis while ruling out other possibilities. The way the clinical experience is stored in memory either facilitates or hinders the ability to formulate the problem.
Expert clinicians store and recall knowledge as diseases, conditions, or syndromes – “illness scripts”.
These representations trigger clinical memory, permitting the related knowledge to become accessible for reasoning. Knowledge recalled as illness scripts has a predictable structure: the predisposing conditions, the pathophysiological insult, and the clinical consequences.
Constructed on the basis of exposure to patients, illness scripts are rich with clinically relevant information. Their content varies for each physician and among physicians.
With experience, clinicians also store memories of individual patients, and the recollection of a particular patient often triggers the recall of relevant knowledge. The defining and discriminating clinical features of a disease, condition, or syndrome become “anchor points” in memory. In the future, recollection of such stored experiences expands the clinician’s ability to recognize subtle but important variations in similar cases.
Both nonanalytic and analytic reasoning strategies are effective and are used simultaneously, in an interactive fashion. Nonanalytic reasoning, as exemplified by “pattern recognition,” is essential to diagnostic expertise, and this skill is developed through clinical experience. Deliberative analytic reasoning is the primary strategy when a case is complex or ill defined, the clinical findings are unusual, or the physician has had little clinical experience with the particular disease entity. Clinicians often unconsciously use multiple, combined strategies to solve clinical problems, suggesting a high degree of mental flexibility and adaptability in clinical reasoning.
By prompting the learner to reason aloud or eliciting the learner’s uncertainties, the clinical teacher can uncover the reasoning process used by the learner. In responses to the teacher’s questions “What do you think?” weak and strong diagnostic reasoning can be readily distinguished.
Learners whose discussion is poorly organized, characterized by long, memorized lists of causes of isolated symptoms, or only weakly connected to information from the case may reason poorly. They do not connect stored knowledge with the current clinical case because they lack either experience with such cases or basic knowledge.
Learners with strong diagnostic reasoning skills often use multiple abstract qualifiers to discuss the discriminating features of a clinical case, comparing and contrasting appropriate diagnostic hypotheses and linking each hypothesis to the findings in the case. The discussion between such a learner and the clinical teacher is often quite concise and may be so abbreviated that its result, the diagnosis, appears to be a lucky guess. In such situations, the teacher may need to ask additional questions that probe the learner’s reasoning or uncertainties to be sure that reasoning, rather than luck, brought the diagnosis to light. Strong diagnosticians can readily expand on their thinking.
Recommendations for Clinical Teachers
Clinical teachers can use several strategies to promote the development of strong diagnostic reasoning skills. The recommendations that follow are drawn from research on how doctors’ reason.
Experience with patients is essential for establishing new connections in memory between learned material and clinical presentations, for developing illness scripts, and for developing the ability to reason flexibly with the use of analytic reasoning and pattern recognition. As learners listen to patients’ stories, learn to transform these stories into case presentations, develop their own illness scripts, and learn to reason about clinical information, teachers can use case-specific instructional strategies to help learners strengthen their skills.
Articulating Problem Representations
Failure to generate an appropriate problem representation can result in the random generation of hypotheses that are based on isolated findings in the case. When the case presentation or discussion is disorganized, the clinical teacher can prompt the learner to create a one-sentence summary of the case.
However, teaching learners to articulate problem representations as an isolated teaching strategy is insufficient. Rather, problem representation must be connected to the type of clinical problem – a connection that facilitates the learner’s retrieval of pertinent information from memory.
In the teaching environment, several learners with different levels of expertise may be involved in the same case, and eliciting the learners’ various problem representations will help the clinical teacher to understand their different perspectives and learning needs. In complex, ill-defined clinical cases, more than one problem representation may need to be considered. The discussion of the different problem representations will help novice learners to appreciate the complexity of the case as well as their own early, limited understanding. Teachers should articulate their own problem representations to demonstrate the type of summary they seek from learners. Teachers can then reason aloud, linking the summary statement to their own illness scripts and highlighting the discriminating features clinicians seek in the history and physical examination for the consideration of appropriate diagnostic possibilities.
Strategies for Comparing and Contrasting
Novice learners often generate numerous possible diagnoses for any given case. To prioritize such a lengthy list, they should be encouraged to compare and contrast possible diagnoses on the basis of the relationship among the actual clinical data on the case, typical presentations for each diagnostic possibility, and the relative probabilities of different diagnoses. Forcing learners to prioritize the list of diagnostic possibilities and explain their justifications helps them to create linkages between the clinical findings in the case and relevant diagnoses, bolstering their ability to develop pertinent illness scripts.
The development of elaborate illness scripts and pattern recognition involves knowledge of the typical presentation of a problem as well as the many atypical presentations or variations on the typical one. It is important for novice learners to begin by creating in memory an anchor prototype of the typical presentation, rather than giving equal consideration to a number of undifferentiated possibilities. Early in their training, medical students should be assigned to evaluate patients with common problems – ideally, problems for which there are prototypical presentations. After the features of the prototype have been solidified in memory, additional clinical exposure to similar problems can offer a basis for comparison with the prototypical case, providing learners with an appreciation of atypical or subtle findings.
Varying Expectations According to Developmental Level
The teacher’s expectation of evidence of strong reasoning should vary according to the stage of training of the learner, but the learner’s developmental level is often related more to the extent of clinical experience with the case at hand than to the year of training. First-year residents, for example, may have clinical reasoning skills that are as advanced as those of senior residents when it comes to common clinical problems that they saw frequent as medical students. Thus, although the stage of training is somewhat helpful to the teacher in determining expectations of and roles for learners, specific questioning strategies are necessary to probe the understanding and elicit the uncertainties of learners at any level. Several different strategies can be used, but open-ended questions are especially useful for assessing the learner’s clinical reasoning ability. Using this or other similar frameworks, clinical teachers can evaluate a learner’s performance on the basis of the expected performance at different developmental levels
Providing Cognitive Feedback
The clinical teacher should provide the learner with specific cognitive feedback. The teacher should point out diagnostically meaningful information in the data on the case, identify redundant or irrelevant findings, and highlight the discriminating features, including their relative weight or importance for drawing conclusions as to the correct diagnosis. When a learner suggests a possible but not plausible diagnostic consideration, the teacher can ask the learner to describe the key features of a prototypical case and then to compare the prototype with the findings in the case at hand.
Encouraging useful Reading Habits
Learners should be encouraged to read about their patients’ problems in a way that promotes diagnostic reasoning, rather than to read about topics in a rote-memorization fashion, without context.
The organization of knowledge stored in memory facilitates the recall of key concepts for application to the next relevant clinical case. To enhance their organization of knowledge and their understanding, novice learners should read about at least two diagnostic hypotheses at the same time, comparing and contrasting the similarities and discriminating features. Clinical teachers should encourage reading that promotes conceptualization rather than memorization and provides learners with an opportunity to share what they have learned, testing what has been understood well enough to be explained and reinforcing the importance of self-directed learning.
Some medical textbooks are better organized than others to encourage learning by comparing and contrasting diagnostic considerations. The judicious use of the original literature, even by novices, can be an effective clinical learning tool, especially when it provides important new organizing principles or pathophysiological insight that have yet to permeate textbooks. Learners should be encouraged to identify progressively broader and more complex issues, explore them more deeply, and apply the principles of evidence-based medicine in arriving at answers.
In summary, clinical teachers can promote the development of diagnostic reasoning while simultaneously diagnosing both the patient’s disorder and the learner’s abilities. To do so, however, they must have an appreciation of clinical learning theory and practice and an accurate understanding of the clinical problem in question. Such an undertaking requires that the teacher accompany the learner to the bedside or examination room and perform an independent assessment of the patient and, at the same time, assess the developmental stage and clinical reasoning ability of the learner.
Ensuring the quality of patient care and modeling professionalism while promoting diagnostic reasoning skills constitute the true art of clinical teaching.
Highlights from the Annotations, updated 16 Jun 2022
- Teachers should promote awareness of interdependence among patients, families, and other members of the health care team when reasoning through clinical problems with learners. The goal of this interdependence is to reach the best diagnostic outcome possible, mindful of how unconscious bias influences clinical reasoning. Interdependence also includes the concept of shared decision making.
- Subsequent research showed that the context can significantly impact diagnostic accuracy.
- In addition, sociocultural theories impacting clinical reasoning have led to the concept that diagnosis is a social activity developed through interactions among patients, health care professionals, and the environment.
- The role of clinical teachers in supporting learners’ effective practice remains critical. Clinical teachers observe learners and provide formative feedback using several approaches.
- A wide array of tools are available to assess clinical reasoning with varying advantages and disadvantages by method.
- Direct observation of learners in the authentic clinical environment is essential. Workplace-based assessments can be used to assess moment-in-time clinical reasoning.
- Innovations in screen-based simulations of patient encounters present emerging opportunities in prospective assessment of reasoning in a standardized manner and at a large scale, although assessing clinical reasoning in simulation cannot replace observations in authentic clinical settings.
- Formative feedback – “no-stakes” feedback for learning – is crucial for learning in clinical settings. An updated approach can be framed as part of an “educational alliance” whereby feedback shifts from a transactional delivery of information to a conversation for improving learning in the context of a supportive educational relationship.
- The diagnostic reasoning process can be considered forward in nature, from data to diagnosis, or backward in nature, from hypothesis to diagnosis (the hypothetico-deductive approach). Some visual diagnoses are made rapidly through pattern recognition.
- Since the publication of this article, published problem solving exercises to illustrate the clinical diagnostic reasoning process have become commonplace. NEJM regularly publishes such exercises in the form of Clinicopathological Conferences (CPCs) and Clinical Problem Solving (CPS) articles.
- Early in the patient encounter, the problem representation activates a search for a list of possible solutions (i.e., a differential diagnosis) using a combination of fast (pattern recognition) and slow (diagnostic schemas) thinking. As data are obtained, the problem representation becomes more focused, and the differential diagnosis is refined. This iterative process results in the natural evolution of an initial unsolved problem into a refined specific summary statement of the patient’s problem with justification for the leading diagnosis and other plausible or “do-not-miss” diagnoses.
- A succinct problem representation connected to a short list of two or three diagnostic possibilities should be encouraged. This shorter differential diagnosis could give learners more time to explain which discriminating findings lead to the prioritization of the leading diagnosis over other less-likely diagnoses.
- Clinicians store knowledge of specific diseases or syndromes in their memory as illness scripts that work for any variation of the disease or condition under consideration. Illness scripts consist of three components: epidemiological risk factors, pathophysiology, and clinical findings.
- Coupling illness script theory with probabilistic reasoning can augment the learner’s ability to estimate the likelihood of a diagnosis.
- The responsibility for patients who need more or less specialized care may be transitioned from one clinician to another. These transitions are common in the modern health care system. When transitions interrupt clinical reasoning process, the opportunity to learn from practice may be lost. Follow-up and feedback may help to minimize diagnostic errors. Physicians are motivated to follow up to learn the outcome of the subsequent reasoning process. In fact, follow-up has been described as part of expert diagnostic practice.
- Teachers should encourage learners to keep track of and follow-up on patients’ outcomes as an important learning strategy to improve clinical diagnostic reasoning.
- The clinical teaching recommendations highlight the development of robust, accurate illness scripts, which is the core principle of clinical reasoning teaching and learning. Because developing illness scripts for every disease is impossible, teachers should emphasize that learners should focus on the development of robust, accurate illness scripts for typical presentations of common and cant-miss diagnoses in their fields of interest. Through experience, learners will revise these scripts throughout their training.
- Illness script knowledge should include a general sense of the following:
- The base rates of diseases (e.g., in adult patients presenting with dyspnea, the most common causes include asthma, chronic obstructive pulmonary disease [COPD], pneumonia, and heart failure)
- The value of clinical findings (e.g., d-dimer is useful for ruling out pulmonary embolism [PE] in a patient with a low probability of disease, but not helpful in ruling out PE in other patients).
- Teaching basic principles of Bayesian reasoning can inform the traditional intuitive and analytic diagnostic reasoning that most clinicians use.
- For effective teaching, meeting learners where they are, or applying specific techniques that target the learner’s level of clinical experience, is essential.
- A qualitative study that examined clinician-educators during medicine rounds identified the following four strategies for cultivating clinical reasoning:
- Emphasizing organization and prioritization
- Accessing prior knowledge
- Thinking aloud
- Analyzing the literature
- Knowledge remains essential, but not sufficient, for effective diagnostic reasoning. The role of context cannot be overstated.
- Teachers should also promote awareness of the characteristics of clinical expertise and its development; breaking down the path to expertise into more explicit steps can help learners understand how to improve their diagnostic reasoning performance.
Conclusion
Acquiring diagnostic reasoning expertise requires practice with many cases in many contexts. Deliberate practice in simulation settings is one approach.
Maximizing quality of clinical experiences requires learners to reflect on their performance to identify gaps in their knowledge and diagnostic skills and develop goals and strategies to fill the gaps.
Learners should select clinical experiences that enable them to improve their areas of diagnostic weaknesses. Because actual practice is limited by the opportunity and randomness of clinical encounters, learners could supplement experiences with clinical problem-solving exercises provided in many journals, applications, and podcasts, focusing on their areas of diagnostic weakness